A technology is known whereby, when a contact detection instrument is inserted into a living body through a hole that has been opened in the surface of the living body and the contact detection instrument comes into contact with an internal organ inside the living body, a signal is output from the contact detection instrument that corresponds to the state of the internal organ with which the instrument is in contact.
For example, in NPL 1, a contact detection instrument is disclosed in which a PVDF film, which is a type of macromolecular piezoelectric material, is attached to a tip of a pair of forceps. A sensor signal that corresponds to the pressure on the PVDF film when it comes into contact with an internal organ is output from the contact detection instrument.